Letters to the Editor

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Sir.—There has been some correspondence in the Velerinary Record recently concerning brucella abortion breakdowns in heifers vaccinated with Strain 19 Brucella abortus. This year we have been alarmed by the sudden occurrence of abortion storms in vaccinated heifers. Brucella abortus has been seen in large numbers in direct smears taken from cotyledons and foetal stomach contents stained by the modified Z-N technique, both in our own practice laboratory and at the Department of Agriculture laboratory. To remove any possible doubt as to the identity of the organism, it has been cultured. Blood samples have been taken from the heifers concerned and sent to the Department of Agriculture laboratory where agglutination titres to Br. abortus were observed at dilutions of up to 1 in 1,280. Our practice here serves 550 dairy farms in one of the most closely stocked areas in New, Zealand. In 18 herds more than 25% of the heifers have aborted owing to brucellosis.     

Comparative studies on the secondary lymphoid tissue areas in the chicken bursa of Fabricius and calf ileal Peyer's patch

The chicken bursa of Fabricius and calf ileal Peyer's patch are thought to be the primary lymphoid organs of B cell development. In the bursa, the existence of secondary lymphoid tissue, called the diffusely infiltrated area, has been recognized. Recently, we have found the presence of a region of secondary lymphoid tissue in the ileal Peyer's patch at the period of the most rapid growth of this organ. In this study, we compared the development of these secondary lymphoid tissue regions in the bursa and ileal Peyer's patch histologically. Before hatching, lymphatic follicle formation occurred in the bursa, but not in the diffusely infiltrated area, where only a small number of lymphoid cells were found. However, during fetal calf development, lymphatic follicle formation occurred not only in the primary lymphoid organ but also in the secondary lymphoid tissue regions. Therefore, the prenatal development of the secondary lymphoid tissue regions of the bursa and ileal Peyer's patch were distinct. After hatching, formation of the germinal center, which contained many CD4⁺ cells, was observed in the diffusely infiltrated area of the bursa. After birth, many CD4⁺ cells and IgG mRNA expression were observed in the lymphatic follicle of the secondary lymphoid tissue regions in the ileal Peyer's patch, but rarely in the ileal Peyer's patch lymphatic follicles. The change of character of these secondary lymphoid tissue regions at the postnatal stage might be dependent on external antigens.     

Recent advances in Brucella abortus vaccines

Brucella abortus vaccines play a central role in bovine brucellosis control/eradication programs and have been successfully used worldwide for decades. Strain 19 and RB51 are the approved B. abortus vaccines strains most commonly used to protect cattle against infection and abortion. However, due to some drawbacks shown by these vaccines much effort has been undertaken for the development of new vaccines, safer and more effective, that could also be used in other susceptible species of animals. In this paper, we present a review of the main aspects of the vaccines that have been used in the brucellosis control over the years and the current research advances in the development of new B. abortus vaccines.     

The future of rural veterinary practice

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It is my privilege, as President of the New Zealand Veterinary Association, to pass comment on the field of veterinary endeavour today at this, the 48th Annual Conference. I do not feel competent to draw conclusions from past trends, or to make wise comments on decisions that have been made which directly affect or impinge on our profession. What I would like to attempt to do is to evaluate the future of rural veterinary practice in this country as we see it today.     

The effect of feeding Hydrogel-95 to emu chicks at hatch

Very little research has been conducted on emu (Dromaius novaehollandiae) in comparison to other types of poultry. Much of the information that is available to producers is very conflicting. Feed restriction for the emu chick for the first 4 d of life is a common practice among the emu industry; however, scientific research has not supported this practice. To the best of our knowledge, the effects of hydration supplements have not been investigated in the emu. Therefore, weights were recorded on emus fed Hydrogel-95 and were compared with emus that were not fed any supplements to determine if the supplement had any effect on the growth parameters of emu chicks. From these 2 field trials, we conclude that feeding Hydrogel-95 significantly decreases weight loss in emu chicks during the first week of life.     

Bracken fern poisoning

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Poisoning of cattle by bracken fern (Pteridium aquilinum) has long been a serious problem on some of the poorer land where eradication of bracken is difficult or uneconomic. The problem occurs also on some better-class land since not infrequently cattle are used to crush out the bracken in the first stages of development of the land or to control regrowth of bracken after burning and sowing down pasture. Grazing horses have also been affected and both cattle and horses have at times heen poisoned whell stall fed on hay which contains bracken.     

流式细胞仪分离精子研究进展

本文概述了近年来用流式细胞仪分离动物X、Y精子的研究进展、存在的问题和应用前景。流式细胞仪分离精子的研究已经取得了很大进展 ,在某些动物 (如牛 )分离的精子已开始用于人工授精。尽管该技术还存在许多亟待解决的问题 ,但随着流式细胞仪的改进和与各项辅助生殖技术 (如手术授精、体外受精、胞质内精子注射、低剂量精子人工授精 )结合 ,性别分离精子必将在实践中得到广泛的应用 ,产生巨大的社会和经济效益     

Myxomatosis

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Madam;–We the undersigned, are veterinarians who have worked in mixed veterinary practice with a cumulative work experience of many years. In this capacity we have undertaken responsibility for the care and treatment of many animals ranging from domestic pets through to production animals.     

Lead poisoning in dogs

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Lead poisoning in dogs is insidious in onset, difficult to diagnose, and frequently overlooked. It is more prevalent in the older and more run-down areas in cities, where deteriorating paint, old lead plumbing, and untidy yards present many opportunities for dogs to acquire toxic amounts. My own practice is situated in one of the older areas of Christchurch and, over the 11 years covered by this paper, I have confirmed 107 cases of lead poisoning.     

祁连县农区黄牛改良现状与发展思考

本文通过对祁连县农区黄牛改良现状分析,从正反两方面总结了成功及不足的经验及一些具体作法。经仔细的测算,得出了农区黄牛改良巨大的经济、社会和生态效益,并针对祁连农区黄牛改良中存在的突出问题提出了祁连农区黄牛改良今后的发展思路。     

Practice management: Is necessity the mother of contention?

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During much of this century veterinary undergraduates were led to believe that because the practice of veterinary science is a profession, after graduation they should never treat clinical practice as a business. This notion was reinforced by their peers, especially. those outside clinical practice, and still exists today. With the dependence of rural practice on the supply and sale of remedies for viability, few practices have ever been run on purely professional lines in New Zealand; but until very recently a minimal level of business ability was adequate to maintain practice viability.     

生殖激素检测应用于国内动物园繁殖监测实践的可行性分析

近年来,随着中国动物园圈养野生动物管理理念、饲养技术、设施设备和人才队伍的不断发展,基于生殖内分泌学基础进行的对人工圈养下野生动物繁殖生理的科学探讨得到越来越多从业者的重视,涉及的野生动物种类也逐渐增加,获得了非常宝贵的初始数据,为动物园行业更加科学规范管理打下了坚实基础。同时,在生殖激素检测的实际操作过程中也凸现出一些现实问题。结合现阶段中国动物园行业具体情况,着重综合近年来部分相关文献资料,回顾国内动物园相关工作进展,对生殖激素分析检测在动物繁殖监测实践中的细节工作进行分析,探讨在日常饲养管理中应用的可行性,提出解决对策,为实践工作提供参考。     

Comparison of gastrointestinal parasite communities in vervet monkeys

Globally, habitat degradation is accelerating, especially in the tropics. Changes to interface habitats can increase environmental overlap among nonhuman primates, people, and domestic animals and change stress levels in wildlife, leading to changes in their risk of parasite infections. However, the direction and consequences of these changes are unclear, since animals may benefit by exploiting human resources (e.g., improving nutritional health by eating nutritious crops) and decreasing susceptibility to infection, or interactions with humans may lead to chronic stress and increased susceptibility to infection. Vervet monkeys are an excellent model to understand parasitic disease transmission because of their tolerance to anthropogenic disturbance. Here we quantify the gastrointestinal parasites of a group of vervet monkeys (Chlorocebus aethiops) near Lake Nabugabo, Uganda, that frequently overlaps with people in their use of a highly modified environment. We compare the parasites found in this population to seven other sites where vervet monkey gastrointestinal parasites have been identified. The vervets of Lake Nabugabo have the greatest richness of parasites documented to date. We discuss how this may reflect differences in sampling intensity or differences in the types of habitat where vervet parasites have been sampled.     

Cystic echinococcosis in the sheep: causes of its persistence in Sardinia

The authors analyse the current epidemiological situation of sheep Cystic Echinococcosis (CE) in Sardinia, where the prevalence of ovine CE is still very high (70%) and this parassitosis is also frequently found in the human population. For this reason Sardinia represents a peculiar model for CE study, because there are particular conditions that allow Echinococcus granulosus to complete its life cycle. Some social and economical factors support the persistence of sheep CE: over 3 million Sarda breed heads are extensively bred; the presence, at farm level, of a strong relationship between dog, sheep and human; the low commercial value of meat coming from adult sheep, whinch results in a large number of sheep being slaughtered at home or on the farm rather than in authorized slaughterhouses. Moreover Sardinia is the only Italian region where partially successful echinococcosis control plans have been applied. The authors suggest some indirect and direct initiatives, including the use of a new vaccine against the development of this metacestode in sheep, to reduce the prevalence of CE.     

Public-health education at Kansas State University

What are veterinary medical and public-health professionals doing to remedy the immediate and impending shortages of veterinarians in population health and public practice? This question was addressed at the joint symposium of the Association of American Veterinary Medical Colleges and the Association of Schools of Public Health, held in April 2007. Thinking locally, faculty and students at Kansas State University (KSU) asked similar questions after attending the symposium: What are we doing within the College of Veterinary Medicine to tackle this problem? What can we do better with new collaborators? Both the professional veterinary curriculum and the Master of Public Health (MPH) at KSU provide exceptional opportunities to address these questions. Students are exposed to public health as a possible career choice early in veterinary school, and this exposure is repeated several times in different venues throughout their professional education. Students also have opportunities to pursue interests in population medicine and public health through certificate programs, summer research programs, study abroad, and collaborations with contributing organizations unique to KSU, such as its Food Science Institute, National Agricultural Biosecurity Center, and Biosecurity Research Institute. Moreover, students may take advantage of the interdisciplinary nature of public-health education at KSU, where collaborations with several different colleges and departments within the university have been established. We are pleased to be able to offer these opportunities to our students and hope that our experience may be instructive for the development of similar programs at other institutions, to the eventual benefit of the profession at large.     

Twenty Years of Experience with Dairy Herd Health in Ontario

This article expresses observations on planned herd health for dairy cattle, based on experience gained in the Ambulatory Clinic practice of the Ontario Veterinary College. The author and his colleagues, especially Dr. R.A. Curtis, have initiated and delivered a preventive medicine approach to veterinary practice in the teaching program and teaching practice for the past 20 years. In addition, herd health presentations have been made to veterinary associations in every province in Canada and to many breed associations and producer organizations. The Canadian food animal veterinarian and his clients have been informed at meetings and by the media of the need, objectives, methods and benefits of dairy herd health and many veterinary practices now offer programs to their clients. Herd health has become a household word in Canada's dairy practices and dairy farms.

A formal herd health program is an important step to achieving total health management; but maximum returns on investment can only be realized after three or four generations of cattle have been reared on the program.

In conclusion, herd health practice has been a very satisfying aspect of veterinary medicine and a profitable and valued service for our clients. Maintenance of health involves the application of all knowledge and procedures which veterinarians have to offer.

     

Immunogenic and protective antigens of Brucella as vaccine candidates

Brucella is an intracellular pathogen that causes abortion in domestic animals and undulant fever in humans. Due to the lack of a human vaccine against brucellosis, animal vaccines play an important role in the management of animal and human brucellosis for decades. Strain 19, RB51 and Rev1 are the approved Brucella spp. vaccine strains that are most commonly used to protect livestock against infection and abortion. However, due to some disadvantages of these vaccines, numerous studies have been conducted for the development of effective vaccines that could also be used in other susceptible animals. In this review, we compare different aspects of immunogenic antigens that have been a candidate for the brucellosis vaccine.     

牧草表观遗传学研究进展

表观遗传是指在DNA序列不变的情况下基因表达发生变化的现象。表观遗传现象与外界环境条件的变化紧密相关,它参与植物的生长发育、胁迫响应、衰老死亡等重要生命过程并在其中起到了关键作用。表观遗传学作为一门新兴学科在近20年间得到了快速发展,成为当前动植物和医学领域的研究热点。目前植物表观遗传学的相关研究主要集中在DNA甲基化、组蛋白修饰、RNA甲基化、染色质重塑和非编码RNA修饰等方面,并取得了许多重要成果。然而,相对于模式植物拟南芥和其他主要作物而言,牧草的表观遗传学研究仍处于起步阶段。因此,开展牧草表观遗传学研究对我国草牧业的可持续发展具有重要意义。本研究对表观遗传学的概念、研究方法、研究内容(包括DNA甲基化、组蛋白修饰、RNA甲基化、染色质重塑和非编码RNA修饰等)及牧草表观遗传学相关研究进行了全面总结和综述,并对表观遗传在草牧业中的发展前景进行了展望。     

论代价意识在科学发展观中的地位和作用

代价问题是我国改革开放和现代化建设中日益凸显出来的现实问题。贯彻落实科学发展观,必须充分认识代价意识的地位和作用。事实上,只要有发展就有代价,代价意识不仅是科学发展观形成和发展的动力源泉,而且是科学发展观正确指导实践的基本理念。